Quantitative analysis of coronary plaque composition by dual-source CT in patients with acute non-ST-elevation myocardial infarction compared to patients with stable coronary artery disease correlated with virtual histology intravascular ultrasound.

RATIONALE AND OBJECTIVES: To quantitatively assess coronary atherosclerotic plaque composition in patients with acute non-ST elevation myocardial infarction (NSTEMI) and patients with stable coronary artery disease (CAD) by coronary computed tomography angiography (cCTA) correlated with virtual histology intravascular ultrasound (VH-IVUS). MATERIALS AND METHODS: Sixty patients (35 with NSTEMI) were included. Corresponding plaques were assessed by dual-source cCTA and VH-IVUS regarding volumes and percentages of fatty, fibrous, and calcified component; overall plaque burden; and maximal percent area stenosis. Possible differences between patient groups were investigated. Concordance between cCTA and VH-IVUS measurements was validated by Bland-Altman analysis. RESULTS: Forty corresponding plaques (22 of patients with NSTEMI) were finally analyzed by cCTA and VH-IVUS. cCTA plaque analysis revealed no significant differences between plaques of patients with NSTEMI and stable CAD regarding absolute and relative amounts of any plaque component (fatty: 20 mm³/13% versus 17 mm³/14%; fibrous: 81 mm³/63% versus 80 mm³/53%; calcified: 16 mm³/14% versus 26 mm³/26%; all P > .05) or overall plaque burden (153 mm³ versus 165 mm³; P > .05), nor did VH-IVUS plaque analysis. VH-IVUS measured a higher area stenosis in patients with NSTEMI compared to patients with stable CAD (76% versus 68%, P = .01; in cCTA 69% versus 65%, P = .2). Volumes of fatty component were measured systematically lower in cCTA, whereas calcified and fibrous volumes were higher. No significant bias was observed comparing volumes of overall noncalcified component and overall plaque burden. CONCLUSION: Plaques of patients with acute NSTEMI and of patients with stable CAD cannot be differentiated by quantification of plaque components. cCTA and VH-IVUS differ in plaque component analysis.